声级计 - 噪声计
Brüel & Kjær的声级计和分析仪为1级测量精度，其设计体现了易用性和前所未有的灵活性。 并且，B&K最新一代的声级计可以通过智能手机直接控制，结合扩展功能的应用程序，您可以针对几乎任何测量任务自定义您的声级计。
60多年前，Brüel & Kjær发明了世界上第一台便携式声级计。直到今天，我们仍然引领行业。
B&K 2245 声级计
B&K 2245声级计是专门针对噪声测量任务的解决方案，简单易用。 该仪器附带了一系列的应用程序，每个应用程序经过量身定制，可为您的特定工作提供帮助。
声级计和噪声计通常用于描述同一种仪器。 在谈到声级计时，主要区别在于精度的分类（由国际标准定义）。 当然，所有Brüel & Kjær的声级计都符合最高的国家标准和国际标准。
多年来，Brüel & Kjær创建了丰富的入门和进阶指南，涵盖了几乎所有与声学和振动测量相关的主题。 作为一家公司，我们热衷于分享知识，因此，我们收集整理了这些知识，免费供您下载。
The analyzer applies Fast, Slow and Impulse (or ‘F’, ‘S’ and ‘I’) time weightings, which are the required weightings according to most international and national standards and guidelines. Environmental assessment standards usually specify which time weighting to use.
Leq is the level that, had it been a steady level during the measurement period, would represent the amount of energy present in the measured, fluctuating sound pressure level. It is a measure of the averaged energy in a varying sound level. It is not a direct measure of annoyance, though extensive research has shown that Leq correlates well with annoyance.
IEC 61672-1 (international standard) defines frequency weightings A, C and Z, but other frequency weightings are occasionally used in specialized applications.
C-weighting is mainly used when assessing peak values of high sound pressure levels. It can also be used, for example, for entertainment noise measurements, where the transmission of bass noise can be a problem.
An octave is a frequency band where the highest frequency is twice the lowest frequency. For example, an octave filter with a centre frequency of 1 kHz admits frequencies between 707 and 1414 Hz but rejects all others. (The name octave stems from the fact that an octave covers eight notes of the diatonic musical scale). A third octave covers a range where the highest frequency is 1.26 times the lowest frequency.
After the signal has been weighted and/or divided into frequency bands, the resultant signal is amplified, and the Root Mean Square (RMS) value determined in an RMS detector. The RMS is a special kind of mathematical average value. It is of importance in sound measurements because the RMS value is directly related to the amount of energy in the sound being measured.
The standard is published in three parts:
- Part 1: Specifications: Requirements for sound level meter performance and functionality for class 1 and class 2 sound level meters
- Part 2: Pattern evaluation tests: Details of the tests necessary to verify conformance to all mandatory specifications given in IEC 61672-1. Used by test laboratories to ensure that instruments meet manufacturers claims.
- Part 3: Periodic tests: Procedures for periodic testing of sound level meters conforming to the class 1 or class 2 requirements of IEC 61672-1:2002
ISO 1996: ASSESSMENT OF ENVIRONMENTAL NOISE
The standard is in two parts:
- Part 1 (2016): Basic quantities and assessment procedures
- Part 2 (2017): Determination of sound pressure levels